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Construction of Trinervitane and Kempane Skeletons Based on Biogenetical Routes
Author(s) -
Kato Tadahiro,
Hirukawa Toshifumi,
Suzuki Takaaki,
Tanaka Masaharu,
Hoshikawa Masahiro,
Yagi Makoto,
Tanaka Motoyuki,
Takagi Shinsuke,
Saito Naoko
Publication year - 2001
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(20010131)84:1<47::aid-hlca47>3.0.co;2-9
Subject(s) - chemistry , biogenesis , yield (engineering) , reagent , derivative (finance) , two dimensional nuclear magnetic resonance spectroscopy , transformation (genetics) , stereochemistry , chloride , triol , organic chemistry , diol , biochemistry , gene , materials science , metallurgy , economics , financial economics
Based on the putative biogenesis of trinervitane‐ and kempane‐type diterpenes ( Scheme 1 ), a biogenetic‐type transformation was simulated by cyclization of 7,16‐secotrinervita‐7,11,15‐triene‐2 α ,3 α ,17‐triol ( 23 ) and of its 17‐chloro derivative 30 . The requisite substrates were prepared from geranylgeranoic acid chloride 6 ( Schemes 2 , 4 , and 5 ). Treatment of 30 with AgClO 4 at −20° provided the trinervitantrienediols 32 and 33 in 68 and 5% yields, while kempadienediol 35 was obtained in 50% yield by the same reagent at +20° ( Scheme 7 ). The structures of the cyclization products were elaborated from detailed inspection of NMR spectra including H,H COSY, C,H COSY, and NOESY ( Tables 1 and 2 ). The conformation of 30 and its plausible cyclization intermediate was discussed with the help of physical evidence, including X‐ray crystallographic analysis.