Alkyl sulfate ester or salt of same

A compound represented by the following formula:

• wherein
• R1 is a methyl group;
• R2 is H and R4 is H or a substituent;
• R3 is a C1-C10 alkylene group optionally containing a substituent;
• n is an integer of 1 or greater;
• p and q are each individually an integer of 0 or greater;
• X is H, a metal atom, NR54, imidazolium optionally containing a substituent, pyridinium optionally containing a substituent, or phosphonium optionally containing a substituent, where R5s are each H or an organic group and are the same as or different from each other;
• L is a single bond, —CO2—B—*, —OCO—B—*, —CONR6—B—*, —NR6CO—B—*, or —CO—, where B is a single bond or a C1-C10 alkylene group optionally containing a substituent, R6 is H or a C1-C4 alkyl group optionally containing a substituent, and * indicates the bond to —OSO3X in the formula;
• a total number of carbon atoms in the compound is 5 to 30;
• and
• the compound excludes 11-keto dodecyl sulphate.