APPROACHES TO THE SYNTHESIS OF CYTOCHALASANS .11. FURTHER TRANSFORMATIONS AND CYCLIZATION ATTEMPTS DIRECTED TOWARDS PROXIPHOMIN
APPROACHES TO THE SYNTHESIS OF CYTOCHALASANS .11. FURTHER TRANSFORMATIONS AND CYCLIZATION ATTEMPTS DIRECTED TOWARDS PROXIPHOMIN
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DOI：
10.1002/hlca.19930760710
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发表时间：
1993-01-01
影响因子：
1.8
通讯作者：
TAMM, C
中科院分区：
文献类型：
--
作者：
BOUTELLIER, M;WALLACH, D;TAMM, C
从碘醇9开始，合成单保护的二醛5（方案2），并通过与氧代膦酸酯15反应转化为17（方案3）。后者是由13。17环化为目标化合物18失败。硫醇22与内酯19的连接也不令人满意（方案4）。因此，使用二烯33和二酯30作为28的起始材料和9作为29的起始材料合成结构单元28和29（方案5和6）。将羟基酸28转化成甲酰基酯46（方案7）。然而，其衍生物48和49与羰基反应性的“Umpolung”的缩合是不成功的，可能是由于空间位阻。
Starting from iodoalcohol 9, the monoprotected dialdehyde 5 was synthesized (Scheme 2) and converted to 17 by reaction with oxo-phosphonate 15 (Scheme 3). The latter was prepared from 13. Cyclisation of 17 to the target compound 18 failed. Also the attachment of thiol 22 to lactone 19 was unsatisfactory (Scheme 4). Therefore, the building blocks 28 and 29 were synthesized using diene 33 and diester 30 as starting material for 28 and 9 for 29 (Schemes 5 and 6). Hydroxy acid 28 was converted into formyl-ester 46 (Scheme 7). However, the condensation of its derivatives 48 and 49 with 'Umpolung' of the carbonyl reactivity was unsuccessful, probably due to steric hindrance.