Sporogen synthesis

Further conversion of (+)-D to sporogen-AO 1 [(+)-134] is summarized in Figure 5.13.21 Similarly, (-)-D gave the unnatural isomer (-)-134. Bioassay of 134 and 134 on Asp. oryzae showed the former to be as sporogenic as the natural sporogen-AO 1, while the latter showed no bioactivity at all. In the same year of 1988, we achieved an enantioselective synthesis of (+)-134, which will not be discussed here.22... 

Figure 5.12 Synthesis of the enantiomers of sporogen-AO 1 (1). Modified by permission of Shokabo Publishing Co., Ltd...

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