p-Toluenesulfonic acid → Diethyl 1,4-dioxaspiro[4,4]nonan-2,3-dicarboxylate

HRID 1659646

Reaction equation

HRID 1659646 reaction equation
CC(CCC[CH2:7][CH2:8][O:9][C:10]([C:12]1[C:17]([C:18]([O:20][CH2:21][CH2:22]CCCC(C)C)=[O:19])=CC=CC=1)=[O:11])C.C1(P(CC2C(CP(C3C=CC=CC=3)C3C=CC=CC=3)[O:46][C:45]3([CH2:65][CH2:64][CH2:63][CH2:62]3)[O:44]2)C2C=CC=CC=2)C=CC=CC=1.C1(=O)CCCC1.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[O:44]1[C:45]2([CH2:65][CH2:64][CH2:63][CH2:62]2)[O:46][CH:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:12]1[C:10]([O:9][CH2:8][CH3:7])=[O:11]

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 8452CyclopentanoneHCID 33934Diisooctyl phthalateHCID 20559778(-)-2,3-Bis(diphenylphosphinomethyl)-1,4-dioxaspiro[4,4]nonane

Product 1

HCID 245393Diethyl 1,4-dioxaspiro[4,4]nonan-2,3-dicarboxylate

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

Example 4 was repeated in which the DTDR was replaced by an equivalent amount of DODDR and the DIOP was replaced by an equivalent amount of (-)-2,3-bis(diphenylphosphinomethyl)-1,4-dioxaspiro[4,4]nonane, prepared by: (a) reacting L-(+)-diethyl tartrate with cyclopentanone in benzene in the presence of p-toluenesulphonic acid to give diethyl 1,4-dioxaspiro[4,4]nonan-2,3-dicarboxylate, b.p. 154°-158° C./6.0 mm., (b) reducing this with lithium aluminium hydride to give (-)-2,3-O-cyclopentylidene-L-threitol, b.p. 124°-130° C./0.2 mm., (c) converting this to (-)-1,4-ditosyl-2,3-O-cyclopentylidene-L-threitol m.p. 109°-115.5° C. by reaction with p-toluenesulphonyl chloride in pyridine and (d) treating with potassium and diphenylphosphine in tetrahydrofuran to give the desired compound m.p. 93°-95° C.

Sources & evidence

ORD record
ord-3c6f9e4605754c61890ae77db3e740b1
Source dataset
uspto-grants-1981_12
Patent number
US04304931

Linked notes

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