ENANTIOSPECIFIC PREPARATION OF [(2R, 6S)-ENDO]-5-AZA-1,10,10-TRIMETHYL-3-OXATRICYCLO[5.2.1.0(2,6)]DECAN-4-ONE BY A NITRENE-MEDIATED ROUTE FROM [(1S)-ENDO]-(-)-BORNEOL AND ITS UTILITY AS A CHIRAL AUXILIARY IN SOME ASYMMETRIC TRANSFORMATIONS

• Published in: Tetrahedron Vol. 48; no. 37; pp. 7979 - 8006
• Main Authors: BANKS, MR, BLAKE, AJ, CADOGAN, JIG, DAWSON, IM, GOSNEY, GRANT, KJ, GAUR, S, HODGSON, PKG, KNIGHT, KS, SMITH, GW, STEVENSON, DE
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier 1992
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; ALKENES; ALDOL CONDENSATIONS; DIELS-ALDER REACTIONS; ALKYLATION REACTIONS; ALPHA; LITHIUM; DERIVATIVES; ACRYLATES
• ISSN: 0040-4020
• DOI: 10.1016/S0040-4020(01)80472-5

Attempted chiral aziridination of styrene by addition of optically-active alkoxycarbonylnitrene 5 derived from [(1s)-endo]-(-)-bornyl p-nitrobenzenesulphonoxycarbonate 4 is reported. No measurable asymmetric induction is observed under the various conditions employed, but in the absence of alkene, a tricyclic oxazolidin-2-one 8 is formed to which preparatively simpler access can be gained by thermal decomposition of azidoformate 7, either in 1,1,2,2-tetrachloroethane (50%) or by spray pyrolysis (58%). The oxazolidin-2-one 8 is demonstrated to be a successful chiral auxiliary by contemporary standards in a variety of asymmetric transformations, including alkylation, acylation, and aldol reactions for which high levels of asymmetric induction are observed. Diethylaluminium chloride-catalysed Diels-Alder reactions exhibit poorer selectivity except for the cinnamoyl derivative 23 which is stereospecific.