Synthetic Routes to (+)-Cassiol and (-)-Cassioside

Abstract

Esta revisão sumariza as seqüências desenvolvidas recentemente para a síntese total das substâncias antiulcerogênicas (+)-cassiol e seu glicosídeo (-)-cassiosídeo. A discussão está centralizada nas estratégias sintéticas e nas metodologias para a construção de centros carbônicos quaternários.This review summarizes the sequences recently developed for the total synthesis of the antiulcerogenic compounds (+)-cassiol and its glucoside (-)-cassioside. The discussion is focused on synthetic strategies and on methodologies for the construction of quaternary carbon stereocenters.

Oxidative allylic rearrangement of cycloalkenols: Formal total synthesis of enantiomerically pure trisporic acid B

“…Furthermore, we have shown that the oxidative allylic rearrangement of cycloalkenols can be carried out easily despite a high degree of functionalization and steric interactions. Therefore, this method should be applicable additionally to the synthesis of a great number of natural products such as cassiol [ 26 – 27 ].…”

Applications of Olefination Reactions to Cassiol Synthesis

“…Cassiol (1), which exhibits a potent antiulcer activity, contains a functionalized cyclohexenone moeity with a quaternary stereogenic center at C-4 and a 2-vinyl-1,3-diol chain, which is connected at the C-3 position. Because of its structural features and pharmacological activity, a number of synthesis have been recorded [1].…”

“…Because of its structural features and pharmacological activity, a number of synthesis have been recorded [1]. Our approach toward the synthesis of 1 involves the C-1'-C-2' double bond disconnection through a carbonyl olefination procedure [2].…”

Studies on a New Synthetic Route towards Cassiol

“…The structural features and pharmacological activity of both products have aroused the interest of synthetic organic chemists and several contributions to its synthesis have appeared in the literature in recent years [1,2]. We have recently developed a rather simple synthetic sequence for the preparation of 5, a precursor of cassiol, by using an olefination reaction of lactol 3 with the 2-benzothiazoleylsulfone 4, under the conditions reported by S. Julia [3] with a 18% yield.…”