3-Hexene-l,2,5,6-tetrol

Hexene-l,2,5,6-tetrol, H-77 erythro-Hex-l-enomc acid 1,4-lactone, 1-49 threo -Hex-2-enonic acid ylactone, A-868 erythro -Hex-2-enono-l, 5-lactone, H-78 threo -Hex-4-enopyranose, H-79... 

Reduction of 3-deoxy-2-0-methyl-D-erj//Aro-hex-2-enose (84, R = H) affords first 3,4-dideoxy-D-gfZj/cero-hex-3-enulose and then, in small proportions, crystalline 3-hexene-D-trans isomer giving the above-mentioned frans-di-O-isopropylidene acetal on condensation with acetone. ... 

Phenyl-conjugated C=C bonds have a strong stretching band at 1625 cm" in CO or C=C conjugation, the band lies at 1600cm" Nonconjugated C=C bonds show bands at 1680-1620 cm" For olefins, a cis double bond in RCH=CHR lies at 1662-1653 cm" S and a trans double bond at 1678 1653 cm" Thus, trans-3-hexene-D-t/irco-l,2,5,6-tetrol has a band (Tipson and Cohen, 1966) at 1653 cm" A terminal exocyclic double bond, as in H2C=CRR, displays a band at 1658-1648 cm" and H2C=CHR displays one at 1648-1638 cm" ... 

This second approach70 was based on the nitromethane synthesis,71 and involved, as the key intermediate, l-C-nitro-l-hexene-D-n6o-3,4,5,6-tetrol tetraacetate (66), previously reported by Sowden and Fischer.77 In re-studying their conversion of D-ribose (64) into the hexenetetrol (66), it was possible70 to secure 2,3,4,5,6-penta-O-acetyl-l-deoxy-l-nitro-D- altritol (65) as crystalline material. When (65) was subjected to the Schmidt-... 

The epimeric addition products (146) obtained from the tetraacetate of l-nitro-D-arafc no-l-hexene-3,4,5,6-tetrol and aniline (see Section IV,2d p. 136) lost two molecules of water per molecule on treatment147 with acetic anhydride in pyridine, and gave 3,4,5,6-tetra-0-acetyl-2-deoxy-2-(phenylimino)-D-arafcino-hexononitrile (147). The... 

The action of sodium methoxide on the tetraacetate of 1-nitro-l-hexene-D-arahino-3,4,5,6-tetrol (193) and the triacetate of 1-nitro-l-pentene-D-ery hro-3,4,5-triol (195) gave, as preponderant products, l-deoxy-2-O-methyl-l-nitro-D-mannitol (194) and l-deoxy-2-O-methyl-1-nitro-D-ribitol (196), respectively.172 As illustrated for the latter example, the configuration of the favored product is that which is expected in terms of approach of the addend from the less-hindered side (Cram s rule). 

---