Abstract
Reliable synthetic routes to isotopically labelled dimethyl [C-13,H-2]diallylmalonates (1) have been developed. Dimethyl diallylmalonates readily undergo transition-metal catalysed cycloisomerisation and the isotopically labelled substrates are expected to be of general utility in the study of the mechanism of such reactions. In the synthetic routes developed, the H-2 labelled allyl chains were introduced by reduction of propargyl functionality with Schwartz reagent. The regio-and stereo-selectivity of such reactions allowing highly selective labelling strategies. The C-13 labelled allyl chains were introduced via Pd-catalysed allylic alkylation of C-13- or H-2-labelled dimethyl allylmalonate anions using [3-C-13(1)]allyl benzoate as the allylic electrophile. Using these methods, dimethyl [ 1,7-(E,E)-H-2(2)]hept-1,6-dienyl-4,4-dicarboxylate (5), dimethyl [2,6-H-2(2)]hept-1,6-dienyl-4,4-dicarboxylate (6), di methyl [1,7-(Z,Z)-H-2(2)]hept-1,6-dienyl-4,4-dicarboxylate (7), dimethyl [1,1,2,6,7,7-H-2(6)]hept-1,6-dienyl-4,4-dicarboxylate (8), dimethyl [1,3-C-13(1),5,7-C-13(1)]hept- 1,6-dienyl-4,4-dicarboxylate (9), dimethyl [1,3-C-13(1),6-H-2(1)]hept-1,6-dienyl-4,4-dicarboxylate (10), and dimethyl [1,3-C-13(1),7-(E)-H-2(1)]hept-1,6-dienyl-4,4-dicarboxylate (11) have been prepared.
Original language | English |
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Pages (from-to) | 1635-1642 |
Number of pages | 8 |
Journal | European Journal of Organic Chemistry |
Issue number | 9 |
Publication status | Published - May 2001 |
Keywords / Materials (for Non-textual outputs)
- allylmalonates
- isotopic labelling
- cycloisomerisation
- C-BOND FORMATION
- ORGANIC-SYNTHESIS
- CYCLIZATION
- COMPLEXES
- ACID
- ALPHA,OMEGA-DIENES
- CYCLOISOMERIZATIONS
- HETEROCYCLES
- FACILE
- RING