In the title compound, C24H24N2O3S, the phenyl rings form dihedral angles of 55.65 (11) and 79.60 (11)° with the plane of the thio­phene ring. The mol­ecular conformation is stabilized by an intra­molecular N—H⋯O hydrogen bond, generating an S(6) ring motif. In the crystal, centrosymmetrically related mol­ecules are linked into dimers by two pairs of C—H⋯O inter­actions.

The title compound, C27H47NO, is a steroid derivative composed of a saturated carbon fused-ring framework with an alkyl side chain. Ring bond lengths have normal values with an average of 1.533 (2) Å, while the cholestane side chain shows an average bond length of 1.533 (2) Å. The three cyclohexane rings adopt chair conformations or close to chair conformations while the cyclopentane ring is twisted. The cholesterol side-chain is fully extended with a gauche–trans conformation of the terminal methyl groups. There are eight chiral centres in the molecule; the absolute configuration of these sites was determined from the structure presented. There are two molecules in the asymmetric unit; in one, the alkyl chain is disordered over two sets of sites [occupancy ratios of 0.50:0.50 and 0.67:0.33].

The synthesis of several novel chiral phosphoramidite ligands (L1–L8) with C2 symmetric, pseudo C2 symmetric secondary amines and chiral Brønsted acids 1a,b has been achieved. These chiral auxiliaries were obtained from commercially available d-mannitol, and secondary amines in moderate to excellent yields. Excellent diastereoselectivites of ten chiral auxiliaries were obtained. The chiral phosphoramidite ligands and chiral Brønsted acids were fully characterized by spectroscopic methods.

The synthetic utility of 3,3′-(3,4-dimethylthieno[2,3-b]thiophene-2,5-diyl)bis (3-oxopropanenitrile) (1) in the synthesis of some novel bis-[1,3,4-thiadiazole] 6a–g and bis-thiazole 10 and 13 derivatives with thieno[2,3-b]thiophene moiety is reported. Antimicrobial evaluation of some selected examples from the synthesized products was carried out and showed promising results.

This paper reports details about the synthesis of a series of novel functionalized symmetrical bis-heterocyclic compounds containing a thieno[2,3-b]thiophene motif. Bis-thiazole derivatives 2, 3a-c and thiazolo[3,2-a]pyridine derivatives 4a-c are achieved. The hitherto unknown dihydrothiophene derivatives 6a-d via bis-pyridimium salt 5 are obtained. Additionally, the novel hydrazonothieno[2,3-b]thiophene derivatives 10a-c are obtained via bis-tosylacetylthieno[2,3-b]thiophene derivative 9. All compounds are characterized by 1H-, 13C-NMR, GCMS, IR, and UV-vis spectrometry. These compounds represent a new class of sulfur and nitrogen containing heterocycles that should also be of interest as new materials.

An efficient and convenient strategy for the enantioselective synthesis of enantiomerically enriched 10-ethyl-7,8-dihydro-γ-ionone isomers (R)-(+)-7, and (S)-(−)-7 are described utilizing a lipase mediated resolution protocol, and reductive elimination of the secondary allylic alcohol as the key step. The enantioselective and diastereoselective lipase kinetic acetylation of 4-hydroxy-γ-ionone derivatives 6a afforded the 4-acetyl-γ-ionone derivatives (−)-8, and the 4-hydrox-γ-ionone derivatives (+)-6a, which are suitable precursors of the desired products. Stereospecific palladium-mediated elimination of allylic acetate provides the target compounds with an excellent enantiomeric excess and yield. Additionally, the novel 4,5-didehydro-α-ionone 13 is obtained from readily prepared (2,6,6-trimethylcyclohexa-2,4-dien-1-yl) methanol 9. The structures of all newly synthesized compounds have been elucidated by 1H, 13C NMR, GC-MS, and IR spectrometry. These compounds represent a new class of odorants that may be of pivotal relevance in industrial perfumery.

A facile and convenient synthesis of some novel hydrazones, schiff’s base and pyrazoles from thieno[2,3-b]thiophene derivatives 1 have been achieved in high yields assisted by microwave and classical methods. The structures of all the title compounds have been elucidated by elemental analysis, IR, MS, 1H-NMR and 13C-NMR. Generally, these findings represent a new class of sulfur and nitrogen moieties that should also be of interest as new materials.