In:
Liebigs Annalen der Chemie, Wiley, Vol. 1983, No. 3 ( 1983-03-15), p. 393-411
Abstract:
Chirale Building Units from carbohydrates, VIII.‐synthesis of the Four Isomeric 1,3‐Dimethyl‐2,9‐dioxabicyclo[3.3.1]‐nonane Starting from different compounds, the syntheses of the four isomeric bicyclic acetals 17, 32, 36 , and 40 ‐ the title compounds ‐ are described. One of these compounds is supposed to direct the attack of the striped ambrosia beetle Trypodendron lineatum Oliv. on conifers. The four compounds can be obtained free of isomers in an uniform synthetic pathway starting from D ‐glucose. Key compound is the acyclic trimethylene dithioacetal 4 , which allows to establish a suitable blocking pattern and to invert the configuration at definite positions. By attaching propylene oxide to the open‐chained sugars of type 13 , the whole chain is built up and leads to the desired products by intramolecular acetalization. The diastereomeric exo/endo pairs 17 and 32, 36 and 40 , respectively, can be separated by physical methods. Therefore, it is sufficient for the syntheses of the four compounds to start with only one given chiral center. The ( S )‐configurated aldehyde 42 can be modified by a Grignard reaction to give a suitable starting material for the syntheses of 32 and 36 . The analogous ( R )‐configurated aldehyde 53 can be synthesized in 75% optical purity via reaction of a chiral modified allylboronate with acetaldehyde
Type of Medium:
Online Resource
ISSN:
0170-2041
DOI:
10.1002/jlac.v1983:3
DOI:
10.1002/jlac.198319830307
Language:
English
Publisher:
Wiley
Publication Date:
1983
detail.hit.zdb_id:
1475010-7
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