IN ETHERS ,

CH₃ - O - CH₃

NOMENCLATURE: 

ALKOXY ALKANE

TEREFORE 4 THIS ANS:  METHOXY METHANE

UNDERSTOOD

NOW FOR

ANHYDRIDE:

NOW   4 this ........

 let us take example:

 1)  CH₃ - CO  - O  - CO -  C₂H₅

ETHANOIC ( 4 C2H5)  METHANOIC (4 CH3) ANHYDRIDE .

note: ethanoic is named first bcoz " E" comes first than " M"

2) CH3 - CO -O- CO- CH3

THEN

ONLY      METHANOIC ANHYDRIDE      (NOT METHANOIC METHANOIC ANHYDRIDE)

3)  C2H5 - C0 - O - CO - C3H7

  then

I HOPE U HAVE UNDERSTOOD...........

THANKU............