The Journal of Organic Chemistry

Chelate selectivity in chelation-controlled allylations. A new synthesis of castanospermine and other bioactive indolizidine alkaloids

H Hamana, N Ikota, B Ganem

Index: Hamana, Hiroshi; Ikota, Nobuo; Ganem, Bruce Journal of Organic Chemistry, 1987 ,  vol. 52,  # 24  p. 5492 - 5494

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Citation Number: 59

Abstract

syntheses of 2 have been accomplished by highly diastereoselective aldol-type reactions which employ a boron enolate of the chiral oxazolidone 4 (coupled with zinc bromide) 2* and tin (I1) enolates of the chiral thiazolidinethione and the achiral oxazolidinethione 6.2 c We now report that the utilization of the tin (I1) enolate of the simple achiral ketone 74 provides a remarkably high diastereoselectivity to afford the key precursor 2 in 295% ...