Synthetis studies on biologically active unsaturated lactones of microbial origin.

1.核内酯的合成：核内酯是由圆核腔菌产生的一系列具有生物活性的癸内酯。以2-甲基环壬酮为原料，经癸烷-9-酮（phoracanthropium）合成芘酯B，建立了一条新的合成癸烷酮的路线. Asperlin及其相关天然产物的合成。(1)（-）-贯众内酯的合成：自然界中存在许多具有生物活性的6-取代-5，6-二氢-5-羟基（或酰氧基）-2H-吡喃-2-酮。为了建立光学活性吡喃酮类化合物的合成路线，以3-三乙基硅氧基-1-丙炔和（S）-1-甲基-2-氧代苯甲酸乙酯为原料，合成了最简单的天然类似物（-）-贯众内酯。(2)天然（+）-苯丙氨酸内酯及其异构体的合成：苯丙氨酸内酯，分离自黑孢霉属，首先通过与上述类似的策略合成。（E，S）-2-苯甲酰氧基-3-戊烯醛与1-锂-3-三乙基硅氧基-1-丙炔反应，合成了一种新的中间体。经保护、脱保护、部分氢化、氧化内酯化、脱保护等步骤得到（+）-苯丙氨酸内酯及其非对映体。(3)（+）-Asperlin及其异构体的合成：（+）-苯丙氨酸内酯经乙酰化、氧化得到（+）-Asperlin和（1 'R，2'S）-异构体。

1. Syntheses of pyrenolides: Pyrenolides are a series of biologically active decanolides produced by Pyrenophora teres. We synthesized pyrenolide B from 2-methylcyclononanone via decan-9-olide (phoracantholide) and established a new synthetic route to decanolide skeleton.2. Syntheses of asperlin and related natural products.(1) Synthesis of (-)-osmundalactone: there are many biologically active 6-substituted 5,6-dihydro-5-hydroxy (or acyloxy)-2H-pyran-2-ones in nature. To establish a synthetic route to optically active pyranones, (-)-osmundalactone, the simplest natural analog, was synthesized from 3-triethylsiloxy-1-propyne and (S)-1-methyl-2-oxoethyl benzoate, which was derived from 2,3-O-cyclohexylidene-D-glyceraldehyde.(2) Syntheses of natural (+)-phomalactone and its isomers : Phomalactone, isolated from Nigerospora sp., was firstly synthesized by a similar strategy as above. (E,S)-2-Benzoyloxy-3-pentenal was reacted with 1-lithoi-3-triethyl-siloxy-1-propynr. After several steps including protection, deprotection, partial hydrogenation, oxidative lactonization and deprotection, (+)-phomalactone and its diastereomer were obtained.(3) Synthesis of (+)-asperlin and its isomer : Acetylation of (+)-phomalactone followed by oxidation afforded (+)-asperlin and (1'R,2'S)-isomer.