TY - JOUR
T1 - A novel synthesis of branched high-molecular-weight (C+40) long-chain alkanes
AU - Lehmler, Hans Joachim
AU - Bergosh, Robert G.
AU - Meier, Mark S.
AU - Carlson, Robert M.K.
PY - 2002
Y1 - 2002
N2 - Many biological and geochemical questions remain concerning the structures, functions, and properties of naturally occurring high-molecular-weight (C40+) alkanes with various mid-chain alkylation patterns. Above C40, these alkanes are exceedingly difficult to separate and purify, and syntheses can be blocked by the low solubility of intermediates. To overcome these problems, a facile three-step synthesis employing the alkylation of 1,3-dithiane with a suitable a, v-dibromoalkane was developed. Bisalkylation of the bis(dithianyl)alkane intermediate with the appropriate 1-bromoalkane and subsequent desulfurization with Raney nickel furnished the desired long-chain alkane. Long-chain alkanes modified at mid-chain and/or symmetrically near the chain termini (or unmodified, i.e., long-chain α, ω-paraffins) are accessible by the selection of appropriate bromoalkanes. Nine mid-chain methylated (C38H78 to C53H108), one symmetrical terminal-chain dimethylated (C40H82), and fourlinear (C44H90 to C58H118) long-chain alkanes were synthesized by using this approach. High-temperature gas chromatography (HTGC) was found to have important advantages for evaluating the purity of the synthetic high-molecular-weight alkanes.
AB - Many biological and geochemical questions remain concerning the structures, functions, and properties of naturally occurring high-molecular-weight (C40+) alkanes with various mid-chain alkylation patterns. Above C40, these alkanes are exceedingly difficult to separate and purify, and syntheses can be blocked by the low solubility of intermediates. To overcome these problems, a facile three-step synthesis employing the alkylation of 1,3-dithiane with a suitable a, v-dibromoalkane was developed. Bisalkylation of the bis(dithianyl)alkane intermediate with the appropriate 1-bromoalkane and subsequent desulfurization with Raney nickel furnished the desired long-chain alkane. Long-chain alkanes modified at mid-chain and/or symmetrically near the chain termini (or unmodified, i.e., long-chain α, ω-paraffins) are accessible by the selection of appropriate bromoalkanes. Nine mid-chain methylated (C38H78 to C53H108), one symmetrical terminal-chain dimethylated (C40H82), and fourlinear (C44H90 to C58H118) long-chain alkanes were synthesized by using this approach. High-temperature gas chromatography (HTGC) was found to have important advantages for evaluating the purity of the synthetic high-molecular-weight alkanes.
KW - Bran-ched alkane
KW - Dithiane
KW - Linear alkane
KW - Long-chain alkane
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U2 - 10.1271/bbb.66.523
DO - 10.1271/bbb.66.523
M3 - Article
C2 - 12005044
AN - SCOPUS:0036490453
SN - 0916-8451
VL - 66
SP - 523
EP - 531
JO - Bioscience, Biotechnology and Biochemistry
JF - Bioscience, Biotechnology and Biochemistry
IS - 3
ER -